Investigation of the Superconducting Gap Structure in SrFe$_2$(As$_{0.7}$P$_{0.3}$)$_2$ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis

Hideyuki Takahashi; Tatsunori Okada; Yoshinori Imai; Kentaro Kitagawa; Kazuyuki Matsubayashi; Yoshiya Uwatoko; Atsutaka Maeda

doi:10.1103/PhysRevB.86.144525

paper

Investigation of the Superconducting Gap Structure in SrFe $_{2}$ (As $_{0.7}$ P $_{0.3}$ ) $_{2}$ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis

arXiv:1207.3155 · doi:10.1103/PhysRevB.86.144525

Abstract

We measured the microwave surface impedances and obtained the superfluid density and flux flow resistivity in single crystals of a phosphor-doped iron-based superconductor SrFe $_{2}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$ single crystals ( $x = 0.30$ , $T_{c} = 25 K$ ). At low temperatures, the superfluid density, $n_{s} (T) / n_{s} (0)$ , obeys a power law, $n_{s} (T) / n_{s} (0) = 1 - C (T / T_{c})^{n}$ , with a fractional exponent of $n = 1.5$ -1.6. The flux flow resistivity was significantly enhanced at low magnetic fields. These features are consistent with the presences of both a gap with line nodes and nodeless gaps with a deep minimum. The remarkable difference observed in the superconducting gap structure between SrFe $_{2}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$ and BaFe $_{2}$ (As $_{1 - x}$ P $_{x}$ ) $_{2}$ in our experiments is important for clarifying the mechanism of iron-based superconductivity.

Investigation of the Superconducting Gap Structure in SrFe $_{2}$ (As $_{0.7}$ P $_{0.3}$ ) $_{2}$ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis

Abstract

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Investigation of the Superconducting Gap Structure in SrFe2​(As0.7​P0.3​)2​ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis

Abstract

References in corpus (30)

Cited by in corpus (14)

Investigation of the Superconducting Gap Structure in SrFe $_{2}$ (As $_{0.7}$ P $_{0.3}$ ) $_{2}$ by Magnetic Penetration Depth and Flux Flow Resistivity Analysis